O.C., interesting. There is one thing about their description that I find a little disconcerting. "No friction" What I want to know is how much does this light slow me down, esp the one that stays on all the time. If it indeed does not slow me down, then with a little ingenuity, I should be able to rewire the generator to say a BB mounted (Cancellara style ) motor. Later editions could have the magnets upsized until the power generated exceeds pedaling power. The dream of inventors forever.

Ben - I guess no friction compares it to the dynamos of old - see the picture I posted near top of thread.

Say your name is CK, you put out a measly 200 Watts (give or take). A typical modern bright bike light may be on order of 2 Watts. So you lose about 1% of your power output to being safe assuming 100% efficiency of the lighting system, which should be pretty close for a non-friction based system such as this.

I poked around their website. The flashing units use about a 1/4 watt which they claim adds up to inches elevation gained per mile. Elsewhere, they talk of studies showing much reduced accident rates in daytime using these lights. (My observation: obnoxiously bright jerseys without patterns work better still but any pattern will act as camouflage in the right lighting - often in bright daylight under trees.)